I would add approx. 10 % of the powder by weight normally 1 lb/gallon of clear. They work much better if you print a smooth white underbase down first with the glow ink on top if going on a dark shirt, it glows much brighter that way. Most of that powder is pretty grainy, would not go finer than a 156 or so mesh. The thicker you print it the brighter the glow as well.